Ⅰ型变态反应动物模型内源性抗IgE抗体的诱导及其对血清IgE水平的抑制作用

INVESTIGATION ON INDUCTION OF AUTO-ANTI-IgE ANTIBODY AND ITS INHIBITORY EFFECT ON SERUM IgE ANTIBODY LEVELS IN TYPE Ⅰ ALLERGIC REACTION ANIMAL MODEL

２５只白兔用卵清蛋白为抗原经全身和鼻粘膜局部免疫，４ｗ后其中１７只动物血清卵清蛋白特异性ＩｇＥ抗体上升到免疫前的５倍以上，并经抗原刺激鼻粘膜诱发出打喷嚏样反应、流清涕等变应性鼻炎样临床症状。这１７只动物用作Ⅰ型变态反应动物模型，其中９只进一步用制备的异种基因型ＩｇＥＦｃε片段为抗原免疫。２ｗ后在血清中检测到较高浓度的抗ＩｇＥ抗体，同时伴有血清总ＩｇＥ抗体浓度下降，上述变化持续观察１０ｗ无明显改变。提示异常增高的ＩｇＥ抗体水平可通过诱导机体产生内源性抗ＩｇＥ抗体的方式抑制。

Twenty-five rabbits were immunized with oval albumine antigen conjugated with Freund's complete adjuvant. The serum IgE levels of 17 out of 25 rabbits enhanced 5￣6 times higher than those before immunization, and coincided with sneeze-like reaction as well as quantity of nasal discharge etc after nasal challenge with specific antigen.These 17 rabbits were used as typeⅠallergic reaction animal models and randomized into two groups.One group was regarded as test group, and was immunized with isotype IgE Fcε fractions that conjugated with heyhole limpet hemocyanin. Another group was regarded as control group, and was treated with normal saline. One week after the second injection,the serum anti-IgE antibody levels enhanced, and two weeks later, the anti-IgE antibody levels enhanced significantly which lasted for at least 10 weeks, meanwhile the IgE antibody of serum was depressed significantly that coincided with the higher anti-IgE antibody levels. The results of the present study indicate that unusually enhanced IgE levels may be depressed by induction of endogenous anti-IgE antibody.